1. Field of the Invention
The present invention relates to methods for manufacturing a perpendicular magnetic recording head that records magnetic data on a recording medium such as a disc by applying a magnetic field perpendicularly onto a medium surface of the recording medium. In particular, the present invention relates to an easy method for manufacturing a perpendicular magnetic recording head that can record magnetic data in narrower tracks on the recording medium.
2. Description of the Related Art
FIG. 12 shows a magnetic recording head used in a perpendicular magnetic recording device. Perpendicular magnetic recording, in which a recording medium is magnetized perpendicularly to its medium surface, enables the recording of magnetic data at a higher density than longitudinal magnetic recording, in which a recording medium is magnetized longitudinally to its medium surface.
FIG. 12 is a sectional view of the magnetic head used in the perpendicular magnetic recording device. FIG. 13 is a front view of the magnetic head in FIG. 12. The sectional view of FIG. 12 is taken along dotted-chain line XII-XII in FIG. 13 in the direction of the arrows.
A magnetic head H is provided on a trailing side surface of a slider that floats or slides on a recording medium.
This magnetic head H includes a main magnetic pole layer 1 and a return path layer (auxiliary magnetic pole layer) 2 provided on the main magnetic pole layer 1. The main magnetic pole layer 1 and the return path layer 2 are composed of a ferromagnetic material.
An end surface 1a of the main magnetic pole layer 1 and an end surface 2a of the return path layer 2 are separated at the front surface of the magnetic head H by a predetermined distance. The main magnetic pole layer 1 and the return path layer 2 are magnetically connected by a magnetic connection 1b. 
The main magnetic pole layer 1 and the return path layer 2 are separated by a nonmagnetic insulating layer 3 composed of an inorganic material such as Al2O3 and SiO2. A coil layer 4 composed of a conductive material such as Cu is formed in this nonmagnetic insulating layer 3.
The end surface 1a of the main magnetic pole layer 1 has a sufficiently smaller area than the end surface 2a of the return path layer 2.
A magnetic flux φ is therefore concentrated at the end surface 1a of the main magnetic pole layer 1 to record magnetic data onto the opposite area of an outer hard film Ma of a recording medium M. The recording medium M is, for example, a disc, and includes the hard film Ma, which has high residual magnetization, and an inner soft film Mb having high magnetic permeability. The magnetic field φ, which is generated from the main magnetic pole layer 1, passes through the soft film Mb to enter the return path layer 2.
The return path layer 2 has a projection 2b extending toward the main magnetic pole layer 1. This projection 2b can suppress the divergence of the magnetic flux φ passing from the main magnetic pole layer 1 to the return path layer 2 through the recording medium M. This magnetic head H can therefore clearly define the edges of recording tracks on the recording medium M to achieve narrower tracks for higher recording densities. Japanese Unexamined Patent Application Publication No. 2002-92820 discloses a perpendicular magnetic recording head of this type.
This publication, however, does not specifically disclose a method for manufacturing such a perpendicular magnetic recording head.